Hydraulic brake device



Aug. 28, 1951 s. 4sEvERlNl 2,556J47 HYDRAULIC BRAKE DEVICE Filed Jan. e, 1949. 2 sheets-sheet 1 /FP/a le mee/Aff `Aug. 28, 1951 1 s, :slavi-:Rum- 2,566,147

HYDRAULIC BRAKE DEVICE- Filed Jan: 6, 1949 2 SheEts-Sheet 2 Patented Aug. 28, 1951 HYDRAULIC BRAKE DEVICE.

Sergio Severini, Rome, Italy, assigner to Oiiicina Meccanica e Riparazioni Omera Societ a. R. L., Rome, Italy, a company of Italy Application January 6, 1949, Serial No. 69,507 In Italy January 26, 1948 Claims. (Cl. 303-84) Subject matter of the present invention is an improvement in hydraulic braking devices, which enables to secure the continuity and the eiiiciency during the operation of similar installations even in the case of break-downs or ruptures taking place in any of the elements of the said installaion.

Such improvement consists in aldevice suitable for being tted upon any industrial machine comprising hydraulically operated elements, yet particular description will be given of its application upon the brake installation of a motorcar.

In the common braking installations of motor vehicles, as a rule, a pump is connected with a set of pipings having their terminals close to the single wheels. In the case of such actually used arrangement, should an accidental rupture take place in any of the pipings containing the liquid which connects the pump with a wheel, the braking system, taken as a whole, becomes inefficient and liable of giving origin to serious inconveniences, particularly if the breakdown is during the motion of a vehicle.

Object of the present invention is to contrive a device to be inserted in the braking installation to the end of avoiding the possibility of similar incidents taking place, As a matter of fact, should during the motion of a motor-vehicle, come about the rupture of the piping relative to a wheel, in virtue of the invention, such piping becomes selfactingly cut off the brake-circuit, the latter preserving its full efliciency in regard of the remaining wheels.

The characteristic features of the device, as disclosed hereunder, render possible that the braking actionremains eicient even in the case of ruptures or breakdowns taking place in more than one of the pipings.

The, braking action upon those wheels in regard of which the connection have remained efiicient, remains steadyV and constant even when the breakdowns or ruptures above mentioned have taken place.

The device forming the object of the present invention can be easily inserted in any already operating braking-installation, it being adaptedA to be fitted either directly on the pump-body or in another point of the framing in between the pump and the wheels, which might be considered as the most suitable for the given type of installation; in such a case, obviously, the device itself must be connected with the installation by means of opportunely chosen pipings. Correspondingly with` the actual tendency in the motor vehicle manufacture of creating devices allowing the ap- 2 plication upon the iront wheels of a brakingpower higher than that applied upon the rearwheels, the device can be embodied in such a way as to consent such a possibility. Y

Lastly, the device can be fitted with a valve adapted to consent the maintenance inside the pipings, of a given initial pressure which prevents the said pressure from being discharged along the piping broken down, even when the eventual rupture is not a sudden one but a one taking place by progressive losses.

The device forming the object of the vpresent invention is illustrated in the annexed sheets of drawing, wherein:

Figure 1 illustrates the device in 'a rst form of practical embodiment, partly in elevational and partly in sectional View;

Figure 2 is a section on the line 2-2 of Figure 1 (wherein the piston is shown in elevation);

Figure 3 shows in sectional view, the position assumed by the organs of an element of the-device iollowing a breakdown or a rupture taken place in the relative hydraulic piping;

Figure 4 illustrates `partly in elevation and partly in section, another form of practical embodiment of the device consenting to exert the the hydraulic control pump.

The body of the device is provided with three cylindrically shaped chambers 3 which are in communication with the pump, through the bores 4 and the canal 5.

The chambers 3 are illustrated in the number 1 of three, inasmuch as in the case in question, one

of the said chambers has been contrived as being connected with the two front wheels, whereas each of the remaining ones is in connection with one of the rear wheels.

It being however obvious that the number of the chambers may vary between a minimal number of two and a maximal number corresponding to the number of the Wheels to be braked.

The chambers 3 are preferably drilled to a diameter equal to the inside diameter of the cylinder of the pump, and in it is snugly sliding the piston 6 having its outside surface profiled in ton. The end of the chambers 3 is screwed in I? order to receive a flange I0, which lis screwed too and which is provided With a se't of bores I`I for the passage of the liquid. "The vflange 'It has a small central boss I2 on whi'chis engaged the spiral spring I3. lOn the face of the said :boss Ii2 is wedged a small rubber cylinder I4 projectingslightly from the plane of the face itself, and which is provided there to the end of getting squeezed so as to obstruct the axial bore 'I5 of the piston, when the device enters its operative stage. fIn the wall LI'6 of the body -I 'of the'device 'is imade a ln'umber fof holes Acorresponding with `leach of the chambers 3, through 'which :holes can penetrate the point 'of la ipin lI'I ,provided with foollar I8 vv'vhere'uponis exerted 'the intrinsic l'oad l* fof aspri'ng .I9 lengaged on 'the pin itself.

The pins vII'I are iheld Lin place with the 'holes iof 4the body `I byfa transversalelement 2li, 'fixed on the body 'itself '-by means of 'the screws 2l. Such `vsaid velern'ent is iprovided -with recesses 22 which contain :the Vtips '-0'f the said pins Il fon 'which are `engaged the springs I`9.

Under normal operative conditions, the ends of the pins I'I by projecting themselves in'to the chambers `3 bear against the :cylindrical Vsurface .io'f'th'e-pisto'n 6.

On to the ange IIl arefscrewed the ljoints 23 o'f 'the p'ipingslleading "to 'the -Ivar-ions wheels to be braked.

-Fromian examinatibnof the *Figures l, 2 and 3 Vbec'o'me vclear falso the operational way of t-hezde- "-vice fformin'g fthe `cibec't of .the invention.

When the 'braking Y.installation is eilcient in v`all its parts, and when all the pipin'gs are lilled up with brake-liquid, the piston `ti is enabled to i.

iaccom-plish, 'under lthe action of the actuating pump 2, an 'excursion which has a maximal vvalue corresponding tothe'heightfof the cylindrical zone i8; Vin'the practice,such an excursion will turn out fas always l'remarkably in'ferior'to the said maxi- 'mal value.

Should any rupture take place, in one of the pipings corresponding to EVa'ny'of the chambers 3, at v"the moment Uf 'the braking, as the relative -.piston '6 meets 'withno resistance :along'its stroke, it I-w-ill be able-of accomplishing v-such an excursion as to be brought in contact with the vsmall r-ubber cylinder I4, .in'the :position illustrated by 'the Figure 3.

fDuringfsuchfstroke, thel'endof the `pin `I l, upon reaching at the extremity of the-cylindrical surtace '8, and under -the '-action of the spring I9 ...penetrates into the-groove 9of `the-piston Ei block- --ing `the latter in position of closure. The small rubber cylinder I4, under lthe action of the hydraulic pressure, gets v.squeezed to such `an eX- tent as to allow that Ythe piston 6 and the boss lI2 are pressing against=each other. One obtains thus the hermetical sealing 'of the `axial hole I5 lavoiding every possible 'leakage of liquid ytoward the broken pipe, whereas the braking element,

:connected therewith, lis hence secluded from the operation (of the installation which continues to be eicient as far as the remaining chambers are concerned. At the repristination of the'eiiciency of the apparatus, the pins I1 may be manually set back into their initial position.

Since the rupture of one pipe might also be unnoticed by the driver, there could be foreseen the application of a device, none illustrated in the figure, serving for both luminous and acoustical "signaling, entering automatically in operative phase under the action of the pin, which is pushed forward to block the corresponding piston in position of closure.

In an identical way, also in the example illus- 'trated inthe gures, the chambers 3 are set side `vby side, it being however obvious that they might .assume any other :position relative to each other; also 'the device could be arranged in any way whatever (upright, lying on its side, upside down).

:The thus vfar disclosed example has illustrated a device comprising three cylindrical chambers of lequal diameter, hence adapted to exert identical braking actions upon the elements undergoing Vthe said faction.

signed to slide inside the chamber,have two different diameters, and precisely thatfof the zone -25 ywhich receives the pressure of the pump is greater than the diameter of lthe zone 2'I which is pressing yupon the liquid operating the braking actionupon -the front wheels.

VIn .this Vway the braking-powerupon these latter will turnaout higher. :In order Ato allow `the -operation of such a differential piston, inthe tchamber -24 Tis introduced a bushing w23, 'which is held in place by the fai-ixiliarybl the `flange 29,

screwed into the `body I of ithefdevice.

The insided'iameterof the v1bushing 2S is equal to the outside Oneof :the zone 21, minus the allowances made for the sliding `of Tthe `,piston in the said bushing.

VAlso the rubber yringf-fengaged on the piston 25 is smaller than the rubberring i engaged on the samepiston onzthepumps side.

Figure 5 illustrates at last the case in which the flange II) is fitted with awalve enabling to maintain inside 'the -pipes an-initial pressure'preventingthis `latter from -being 'discharged through the deteriorated pipes in the 4case of not a sudden rupture but of a gradually .proceeding leak age.

In such .event, the small 'rubber cylinder I4 (Figure -5) is `borne ona Ysmall metallic "plug 30, vmade e. g. of bronze, -whereon is engaged -the spiral spring i3. The said small plug 30, is provided, in its upper part, with a cavity in which is introduced the internally `concavous profiled rubber 3I.

In `the portion of the plug 30, which `corresponds to such-cavity is bored the diametral `hole -33 whichallows the l.passage'of the oil after previous compression of `the extremity of the said profiled Yrubber l:il and -the lhole 34 of the rubber disc 32 set on top of the small plug 30.

At lthe .end of the braking the oil tends to accomplish the inverted itinerary through the hole 34 of Vthe rubber disc 32. Yet, there being no possibility to ilow through the bore 33, it will squeeze the packing 3| and compress the spring |3 causing the small plug 30 to withdraw. In

this manner the oil is allowed to pass in between the head of the small plug and the wall of the flange 29. For such purpose the head of the small plug 3|) whereon is resting the rubber disc 32 instead of having a circular cross-section possess a hexagonal cross-section.

, Obviously, the operationof the contrivance becomes manifest in respect of the pipings efficient as compare with the deteriorated ones in regard of which the said contrivance will not become operative.

I claim:

l. A safety device for hydraulic brakes particularly for motor vehicles, comprising a plurality of chambers, means for supplying brake fluid under pressure to one end of each of said chambers, screw plugs for closing the other ends of each of said chambers, each of said plugs having central opening and a connection for piping said fluid to a wheel, a piston in each of said chambers, each of said pistons having an axial cylindrical bore extending from one end thereof and terminating in a frustro-conical portion near the other end thereof, and a capillary bore extending through said other end to said frustroconical portion, rubber packing members on each end of said pistons for sealing against the walls of the chambers, a cylindrical member located in each of said chambers near said screw plugs, a spring surrounding each of said cylindrical members and of a length greater than the length of the cylindrical member so as to abut the head of the piston, and each of said cylindrical members having a central cavity with a small rubber cylinder wedged therein, said rubber cylinders projecting from said cavities and serving to close the axial bore of the piston when said piston has eected the complete forward stroke allowed inside the chamber.

2. A safety device for hydraulic brakes particularly for motor vehicles, comprising a plurality of chambers, means for supplying brake fluid under pressure to one end of each of said chambers, screw plugs for closing the other ends of each of said chambers, each of said plugs having central opening and a connection for piping said fluid to a wheel, a bushing located adjacent each of said screw plugs for reducing the diameter of said chambers at the end portion thereof, a piston in each of said chambers, said pistons being axially bored through their lengths and having an end portion thereof of less diameter than said bushings, rubber packing members on each end of said pistons for sealing against the walls of said chamber and said bushing respectively, a cylindrical member located in each of said chambers near said screw plugs, a spring surrounding each of said cylindrical members and of a length greater than the length of the cylindrical member so as to abut the head of the piston, and each of Said cylindrical members having a central cavity with a small rubber cylinder wedged therein, said rubber cylinders projecting from said cavities and serving to close the axial bore of the piston when said piston has effected the complete forward stroke allowed inside the chamber.

3. A safety device for hydraulic brakes particularly for motor vehicles, comprising -a plurality of chambers, means for supplying brake fluid under pressure to one end of each of said chambers, screw plugs for closing the other ends of each of said chambers, each of said plugs having central opening and a" connection for piping said lluidv to a wheel, a piston in each of said chambers, each of said -pistons being axially `bored through its length and having a rubber packing member on' each end thereof for sealing against the walls of the chamber, said screw plugs each having a cylindrical member integral 'therewith and extending into said chamber, said cylindrical members leach having a plurality of bores leading from'said chamber to the central openings of said plugs, a spring surrounding each of said cylindrical members and of a length greater than the length of the cylindrical member so as to abut the head of the piston, and each of said cylindrical members having a central cavity with a small rubber cylinder wedged therein, said rubber cylinders projecting from said cavities and serving to close the axial bore of the piston when said piston has effected the complete forward stroke allowed inside the chamber.

4. A safety device for hydraulic brakes particularly for motor vehicles, comprising a plurality of chambers, means for supplying brake fluid under pressure to one end of each of said chambers, screw plugs for closing the other ends of each of said chambers, each of said plugs having central opening and a connection for piping said fluid to a wheel, a piston in each of said chambers, each of said pistons being axially bored through its 'length and having a rubber packing member on each end thereof for sealing against the walls of the chamber, a cylindrical member located in each of said chambers near said screw plugs, each of said cylindrical members having a frustro-conical cavity therein with radial holes extending through the side walls of said cavity, a concavous profiled rubber member in each of said frustro-conical cavities adhering to the walls thereof, a spring surrounding each of said cylindrical members and of a length greater than the length of the cylindrical member so as to abut the head of the piston, and each of said cylindrical members also having a central cavity with a small rubber cylinder wedged therein, said rubber cylinders projecting from said cavities and serving to close the axial bore of the piston when said piston has effected the complete forward stroke allowed inside the chamber.

5. A safety device for hydraulic brakes particularly for motor vehicles, comprising a plurality of chambers, means for supplying brake uid under pressure to one end of each of said chambers, screw plugs for closing the other ends of each of said chambers, each of said plugs having central opening and a connection for piping said fluid to a wheel, a piston in each of said chambers, each of said pistons being axially bored through its length and having a rubber packing member on each end thereof for sealing against the walls of the chamber, a cylindrical member located in each of said chambers near said screw plugs, each of said cylindrical members having a frustro-conical cavity therein with radial holes extending through the side walls of said cavity, a concavous profiled rubber member in each of said frustro-conical cavities adhering to the walls thereof, a rubber disc member located between each of said cylindrical members and said plugs, each of said rubber disc members having a diameter less than the diameter of said chambers and having a central hole corresponding to the central opening in said plugs, a spring surrounding each of said cylindrical members and 7 A off-a lengthfgreater than theY length of the cylindrical: member soas tofv abut the head of. the pis.- ton, and each.V ofv saidI cylindrical members also having a central cavity with' a small rubber cyl'- inder wedged therein, said rubber cylinders projectin-g from said cavities and serving to close the axial b'ore of the piston when said piston has effected the complete' forward stroke allowed inside the chamber.

SERGIO SEVERI-NI.

REFERENCES CITED The following references are of record in; the ii'le of this patent:

UNITED STATES PATENTS Number Name Date 2,166,747 Best July 18, 1939 2,216,570 Hollingshead Oct. 1, 1940 2,253,580 Rabe Aug.v 26, 1941. 10 2,292,925 Bourgeois 1 Aug. 1'1, 1942 

